I dont use an HxC with my Oric, but other users do, so they will be more helpful. In any case, we know this setup should work.

A couple of things that could be of importance, are you using an original Microdisc board? Are you confident it works ok? Are you connecting it to the Oric using an Amplibus? You know about the problems with bus signals...

Another thing I find strange is the error message. I get a "No operating system on disk" when the disk is not bootable (or the disk cannot be read without errors).

The cycle I use is booting, get bars and Oric does not boot, press reset, getting the "insert system disk" insert disk (or select image) and it boots. With cumulus I select the image, then reset, it boots.

Hi jdavis6809,
I have similar hardware for my Atmos and use both a floopy disk drive and the HXC SD floppy drive without any problem, although initially the HXC needed setting correctly on the jumpers and it was also sensitive to a correctly formatted SD card. Anyway if it helps I can suggest a few things to get you moving forward.
1. I can provide you with a 3.5" operating disc (Oric Dos or Sedoric) and this will help you to fully check out your real floppy drive and interface.
2. You could send me your SD card so that I can test it on my functioning system to confirm that all is okay.
3. Happy to provide some further support and photos of my floppy disk configuration if you are still unable to resolve your issues.

Mmmmm... the Microdisc interface follows the Shuggart standard. A flat cable is needed (no twist or modification), just remember to use a floppy which can be set as DS0.

You obviously need a bootable disk. If you cannot make one (you need a win98 box with an internal -no USB- floppy drive). If you can't, you can use a Gotek with the fastfloppy or HxC firmware set as DS0.

I have 2 3.5 floppy drives taken from a PC and I am using a flat cable. The only thing you need is setting one floppy as DS0, which will be drive A or 1 (by default PC's were configured as DS1 as they did not follow the Shuggart norm and they did not use the lines to select ds0-3).

You can alter the cable to ger a similar result, but I am quite sure that the usual twisted PC cable did not work. It was a bit different. I found it easier to set the drive as DS0. So I guess now that this special twist is what you ment?

My Oric shows the typical bars, then I press reset on the controller and the usual screen asking for system disk appears.

I don't think Oric DOS can handle 80 tracks? As far as I know only Sedoric 2.1 (modified by Ray McLaughlin) and onwards can.
(well, maybe Randos or other Stratsed can, but not sure... And the most common nowadays is Sedoric)

Just to hopefully close out this topic, I made up a custom interface cable to test out the Oric Cumana disk interface (using the Oric DOS ROM and Oric Dos) using the later type 1.4Mb (PC) floppy disk drives. This setup worked well and did not appear to have any issues. To be sure of good reliability I used the HD floppy disks with the square hole covered to ensure the disk drive identified the disk as double density (DD). I did not test the cable with a genuine Oric Disk Drive Unit but I am confident it would be okay. I have attached a drawing of the cable configuration in the hope that it may be useful to other Oricians. Note that this setup only allows a maximum of two floppy disk drive units.